880 likes | 1.03k Vues
Joint Workshop 4th Beam Physics Seminar & 9th ATF International Collaboration Meeting Kamogawa, Chiba ken, Sotobo “outside of Bozo Peninsula”, March 19-21, 2003. Joint Workshop. 55 participants : 31 Japan, 8 China, 3 SLAC, 3 Russia, 3 UK , 2 India, 2 Jordan, 1 UCLA, 1 Orsay,1 CERN
E N D
Joint Workshop 4th Beam Physics Seminar & 9th ATF International Collaboration Meeting Kamogawa, Chiba ken, Sotobo “outside of Bozo Peninsula”, March 19-21, 2003 F. Zimmermann
Joint Workshop • 55 participants: 31 Japan, 8 China, 3 SLAC, 3 Russia, 3 UK, 2 India, 2 Jordan, 1 UCLA, 1 Orsay,1 CERN • sponsored by JSPS Core University Program – Beam Physics • (‘Japanese Society for the Promotion of Science’) • JSPS Subprogram: Linear Collider Accelerator R&D (responsible J. Urakawa) • Beam Physics Seminar (1st at IHEP, 2nd at IHEP, 3rd at Nasu (Joint), 4th Kamogawa); China-Japan Collaboration • ATF Int’l Collaboration Meeting (1st at KEK 1996, 2nd at SLAC, …, 7th at Nikkou (2001), 8th Nasu (2002), • 9th Kamogawa 2004 F. Zimmermann
Agenda of Joint Workshop: • Review of ATF R&D • Hardware • Chief Director of JSPS Asian Program – • JSPS R&D • Extraction Line Diagnostics & Experiments • Instrumentation and Beam Physics • Future Plan F. Zimmermann
detailed schedule F. Zimmermann
I will present my impression from all talks & slides from: “Opening Remarks” - Junji Urakawa “ATF Status” - Hitoshi Hayano “Future Plans for ATF Instrumentation” – Marc Ross “Laser Wire R&D and Plans in the Extraction Line” – Grahame Blair “Welcome Talk JSPS” – Tsyuyoshi Enomoto “Comments about ATF Instruments & Future Plan” – Marc Ross “Plans for 2004-2005 ATF Run” – Junji Urakawa “Developments at 2004 ATF Run” - Hitoshi Hayano F. Zimmermann
Accelerator Test Facility this and many following slides from H. Hayano! Damping ring ATF is the largest LC Test Facility E=1.28GeV Ne=1x1010 e-/bunch 1 ~ 20 bunches Rep=1.5Hz X emit=2.5E-6 mm ( at 0 intensity) Y emit=2.5E-8 mm ( at 0 intensity) Linac F. Zimmermann
Low Emittance Tuning • Beam-based optics modeling Q-magnet strength correction in model • Beam based BPM offset measurement Q, SX trim excitation & bump orbit to orbit response • COD correction • Dispersion correction • Coupling correction horizontal kick to vertical response, then skew corrector H. Hayano F. Zimmermann
BPM Resolution Improvement Min. resolution ~ 2µm F. Zimmermann
Vertical dispersion Improvement F. Zimmermann
X to Y coupling Improvement F. Zimmermann
Laser wire beam size monitor in DR 14.7µm laser wire for X scan 5.7µm for Y scan (whole scan: 15 min for X, 6 min for Y) 300mW 532nm Solid-state Laser Fed into optical cavity F. Zimmermann
Beam profile by Laser wire e2 =meas2 - lw2 = e2 – [(p/p)]2 :measured by Q-trim excitation F. Zimmermann
Bunch Length by SR monitor streak camera F. Zimmermann
Energy Spreadby beam size monitor at EXT dispersive point F. Zimmermann
Transverse Emittance by Laser wire < 0.4% y/x emittance ratio Y emittance =4pm at small intensity F. Zimmermann
demonstrated single bunch emittance gex~3.5-4.3 mm (1.4-1.7 nm) gey~13-18 nm (5-7 pm) CLIC target values gex~0.45 mm gey~3 nm ? F. Zimmermann
(<5 ntorr) (>7.6 ntorr) ODR monitor? F. Zimmermann
observed pressure sensitivity in striking contrast to prediction Tor Rauben- heimer, KEK-92-7, 1992 1000 ntorr 10 ntorr 0.1 ntorr “at large amplitudes tail from elastic gas scattering like ~1/y3”? F. Zimmermann
T. Naito et al., “Observation of the Longitudinal Beam Oscillation at ATF-DR” KEK Preprint 2003-73 October 2003 A total intensity 6x1010 the amplitude of the longitudinal oscillation at each bunch (1s) for comparison full bucket size: 1.4 ns rms bunch length: 0.017 ns measured by streak camera similar scatter seen in energy profiles sensitive to rf temperature, suspect HOM F. Zimmermann
gqy gqy F. Zimmermann
BINP-SLAC-LLNL-KEK collaboration on nanometre BPM; thermal noise level 1 nm, measures position and angle F. Zimmermann
X-ray SR monitor real time measurement <20 ms avoids diffraction limit FZP as lens on CCD Measured 6.5-7 micron Expected 5 micron Why? magnification (checked!), vibration, alignment ODR monitor first observation of ODR from slit target SR suppressed by mask 20 micron sensitivity achieved measured beam size too large both ODR & XSR give 20% larger s than laser wire F. Zimmermann
outstanding questions • multibunch emittance increases about 2x faster • with intensity than single bunch emittance • gas pressure effect not consistent with Tor’s prediction • (sensitivity to vacuum much higher than expected, • direct correlation) • performance with wigglers (planned) • e-cloud coating tests in the ATF (M. Ross’ proposal) • what should be measured? F. Zimmermann
ATF Plans for 2004 20 weeks operation JFY 2004 and 2005 April-June: high current multibunch MB emittance study: vacuum scrubbing, high current, x/y emittance by laser wire, longitudinal oscillations nm resolution BPM test: new mover & new cavity electronics compare with nm BPMs from KEK fast feedback test & demonstration: basic test BPM & kicker first, test for 1-3 train extraction, FEATHER -> FONT instrumentation developments ODR, laser wire, X-ray monitor, fast sweep laser (UK) October-December: performance of wiggler magnets From 2005: “ATF R&D 2nd phase” unique studies as determined by GDO F. Zimmermann
(J. Urakawa) F. Zimmermann
Marc Ross F. Zimmermann
Laser Wire R&D +Plans in the ATF Extraction Line G. A. Blair Royal Holloway Univ. London Joint Workshop for 4th Beam Physics Seminar and 9th ATF International Collaboration Meeting 20th March 2004 • Laser-wire at PETRA • Environment at PETRA • Installation of Hardware • First measurements • UK R&D Plans • Extraction Line • Conclusions and Outlook